Sewing machine



Aug. 30, 1949.

R. K. HOHMANN 2,480,734

SEWING MACHINE Original Filed July 18, 1942 VIII/11 111111111 l I K Y x. EJQM H ATTORNEY- Patented Aug. 30, 1949 Richard K. Hohmann, to Sears, Roebuckan poration of New York July 18, 1942, Serial No. 451,422, now Patent No. 2,430,932, dated Novem- Original application ber 18, 1947.

Jamaica, N. Y., assignor d 00., Chicago, Ill., a cor- Divided and this application April 4, 1947, Serial No. 739,436

4 Claims. 1

This application is a division of my prior application, Serial No. 451,422, filed July 18, 1942, which has matured into Patent 2,430,932 dated November 18, 1947, and discloses and claims a sewing machine characterized in part by the incorporation in the hollow sewing machine head or frame of sewing machine parts or adjuncts which heretofore have customarily been external to the head or frame. The object of the invention claimed herein is to provide an improved driving connection between a motor mounted on the base portion of the sewing machine frame and the needle bar actuating shaft mounted on the upper portion of the frame and including a guiding belt within the hollow standard portion of the frame. While the invention claimed herein is not limited to use in a sewing machine having the special characteristics disclosed and claimed in said Patent 2,430,932, it is of a special utility in a sewing machine characterized as above mentioned.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawing and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

Of the drawings:

Fig. 1 is a side elevation of a sewing machine head partly broken. away and in section;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 3 is a partial section on the line 33 of Fig. 1; and

Fig. 4 is a perspective view illustrating details of the drive mechanism.

In the accompanying drawings I have illustrated the use of the improvements disclosed and claimed herein, in a convertible sewing and darn-' ing machine of known type adapted for mounting in a drop head sewing machine cabinet, but the said improvements claimed herein are not restricted to use in sewing machines of said type.

In the preferred form illustrated, the sewing machine frame comprises a main frame casting, which includes a pedestal portion A, a standard A extending up from the pedestal portion, an arm A extending horizontally away from the upper end of the standard and terminating at a distance from the latter in a needle head A and a cylinder arm A extending horizontally away from one side of the pedestal beneath the arm A Detachably secured to the pedestal portion of the main frame casting is a base member A comprising a flat bottom portion, and an uprising rim portion displaced from the cylinder arm A and comprising portions at opposite sides of the latter and a connecting end portion remote from the pedestal. A removable fiat work bed part A may be supported by the cylinder arm A and the rim of the base member A to adapt the machine for ordinary fiat sewing operations, or may be removed to facilitate sewing, darning and repairing operations on tubular work pulled over the free end of the cylinder arm A v The hollow standard A and horizontal arm A portions of the frame are relatively larger in transverse cross section than has been customary heretofore, and are adapted to house mechanism parts heretofore customarily mounted externally of the frame. The sewing machine frame shown in the drawing is also characterized by its formation with a top opening A which extends horizontally for substantially the full length and width of the arm A and across the upper'end portion of the standard A The opening A is normally closed by a readily removable cover B, which is advantageously provided with a spring lever or other yielding retaining device B adapted to releasably secure the cover in place. The standard is also formed with an opening A in its front wall normally closed by a door or cover member C which has an inwardly extending arm C pivoted to the frame at A The opening A is provided to give access to, and to facilitate the use of a bobbin winding mechanism not claimed oridescribed in detail herein, but devised by me and fully disclosed and claimed in said parent application.

The horizontal needle bar actuating shaft D which forms the main driving shaft of the sewing machine is mounted in the lower portion of the chamber space in the arm A and extends across the upper end of the chamber space in the standard A The under bed sewing machine mechanism comprises a hook shaft E mounted in the cylinder am A and carrying a rotary hook E at its front end. A vertically disposed shaft F journalled in the standard A is gear connected at its ends to the shafts D and E and thus fonms means through which the driving shaft D rotates the hook shaft E. As shown, the sewing machine includes a feed mechanism comprising a pair of levers G .exmnding upward through the standard A from about the level of the shaft E, and operatively connected at their upper ends to the driving shaft .D. The said feed mechanism forms no part of the present invention and may be, and as shown is, identical with that disclosed in my prior Patent 2,247,379 of July 1, 1941, and need not be further described herein. It is noted, however, that the manually adjustable lever G which by its angular adjustment determines the direction of the work feed and the length of the stitches formed, extends through a slot formed for the purpose in the central portion of the door 0, and through a portion A of the frame casting which extends directly back of the cover-C when the latter is in its closed position.

The driving shaft D is rotated in normal operation by an electric motor H mounted in the pedestal portion of the frame and connected to the shaft D by a belt H The belt H extends about a driving pulley H on the shaft of the motor H and a pulley I-I surrounding and adapted to be releasably clutched to the driving shaft D as hereinafter described. A guide pulley or idler H 'adjustably mounted :in the standard A engagesthe belt and keeps it taut. The pulleys H and H and belt H are located within the space surrounded by the unitary, standard forming, portion of the main frame casting, which is formed with an opening A through which the idler H may be adjusted and through which the belt H may be manipulated in belt replacing operations. The opening A is normally closed by aremovable cover part a.

.As collectively shown inFigs. l, 2 and 3, the pulley H surrounds an elongated hub portion 1' of the hand wheel I, and is normally secured to said hub pOl'liiOnfbYsEt screws 1 The body portion of the hand wheelI is external to the frame, and its elongated hub 1 extends loosely through an opening A formed in the side of the standard and substantially concealed and closed by the hand wheel I. The pulley H and hand wheel I are releasably clamped to the driving shaft D for sewing operations, or are freed to rotate about the then stationary shaft D in bobbin winding operations, by angular adjustments relative to the shaft D, of a .clamping nut J screwed on the threaded inner end of the shaft D. When the nutJ is rotated in the clamping direction relative to the shaft D, the hub I is clamped between an outwardly extending flange portion of a member K surrounding the shaft D and rigidly secured thereto by set screws and a washer L which is interposed between the head of the clamping screw J and the outer side of the hand wheel I. The outer portion of the bore of the nut J is enlarged to receive the head d of a screw threaded into the end of the shaft D. The screw head if islarger in diameter than the shaft D andis provided to prevent the nut from being inadvertently entirely screwed off the shaft D.

To provide a suitably long bearing for the pulley H and hand wheel I, and to permit their movement to the right, as seen in Fig. 1, to facilitate replacement of the driving belt 1-1 I make use of a bearing sleeve M which surrounds both the elongated hub portion K of the member K and the aligned tubular body of the clamping nut J. Longitudinal slots M formed in the inner end of the member M receive spline ribs K carried by the hub portion K As shown, the member M is also formed at the outer end with longitudinal slots M which receive lateral projections L from the washer L. The outer surfaces of the parts L form extensions of the cylindrical outer surface of the member M and elongate the bearing surface from the hub I when the clamping screw J is backed off and the parts I and H are moved relative to the shaft D into their dotted line positions shown in Fig. 3. Such displacement of the pulley H facilitates manipulations of the belt effected in the course of belt replacement through the framempening A The memberM also provides a spline connection between the clamping washer L and the part K and shaft D which facilitates the clamping of the pulley H to said shaft.

At its inner side, the pulley H is provided with a cylindrical flange H which during the bobbin winding Qperationserves as a driving roll engaged by andfrotatin'g afriction wheel N. The latter is secured on one end of a bobbin winding spindle or shaft N whichhas its opposite end bifurcated to enter the centrol passage of a bobbin which may =bedetaohaibly and frictionally secured to said spindle. The spindle N is journalled in a bearing block N carried by the upper end of an arm 0 which has its lower end journalled on a pivot O anchored in :a supporting :member :P. The latter is vertically disposedinlthestandardA and'adjacent .its lower end :is pivoted -:on a pivot pin P having a threaded extension anchored in 'aframe casting lug-'orprojection A "The shaft N and pivot pinsO 'and P 'rareall parallel to the driving shaft D.

The supporting means for the spindle N to which reference has just been made, form part of the mechanism by which theipulley N'may be adjusted between -positions within the hollow standard A 'in which :it does and does :not operatively engage the flange :I-I o'f'th'e pulley H so as to be rotated byitheiatter, and throughwhich'the spindle may be moved out of the standard A through the :opening 5A to facilitate the mounting of a bobbin on, and removal from the bifurcated :end of said spindle .Ni, as is fully disclosed in my said .prior application.

Toiseparaterthe 'hand'wheelli-from the pulley H and shaft D preparatory to their removal from the frame, it is necessary only to loosen the "set screws 1 remove the screws d, and screw the clamping nut member J off-of theshaftsD. The hand wheel I and bearing sleeve member 'M may then be removed fromrthezmachine,'andthereafter the driving shaft Dmay be displaced 'in'its bearings, to the left-asseen inEig. 1, far enough to clear the pulley H and the latter :maythen be moved upwardly out of the arm A through the opening A The assembly of the above mentioned parts may be effected by operations theireversebf'those just mentioned.

The separable hand wheel land driving pulley H :are formed and associated with the driving shaft D, ina practicallyrsimple'and effective-manner and are characterized by the relative ease with which they may :be "assembled and disassembled. The detachable mounting of the pulley H 'on the :hub of the handwheel I, and the provisions made :for disconnecting them from the drive shaft D, make it possibletolocate the hand wheel outside, and the :pulley within the frame, while permitting the frame opening A through which they are connected, to be substantially smaller in diameter than either the pulley 01' the hand wheel.

While in :accordance with the provisions of the statutes, I have illustrated 'andd'escribed the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in *the form of the apparatus disclosed without departing from the spirit of my invention, as 'set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a motor driven sewing machine the combination with a frame including a base portion, a hollow standard and a hollow arm connected at one end to the upper portion of the standard and extending away from one side of the latter, said frame being formed with an opening at the side of said standard opposite to the first mentioned side and in register with said hollow arm, a needle bar shaft within and extending longitudinally of said arm through said standard and opening, a driving motor mounted in said base portion, a driving connection between said motor and shaft comprising a pulley member mounted on said shaft adjacent and at the inner side of said opening, a hand wheel mounted on said shaft adjacent and at the external side of said opening, means extending through said opening detachably connecting said pulley and hand wheel and clamping means including an actuating element accessible for adjustment at the outer side of said hand wheel for releasably clamping said pulley and hand wheel to said shaft.

2. A sewing machine as specified in claim 1, including an inner clamping member secured to said shaft, a bearing sleeve interposed between said shaft and said hand wheel and pulley and in splined relation with said inner clamping member and an outer clamping member in splined relation with said sleeve.

3. A sewing machine as specified in claim 1, including an inner clamping member secured to said shaft, a sleeve bearing interposed between said shaft and said hand wheel and pulley and comprising a tubular member in splined relation with said inner clamping member and including spaced apart outer end portions extending longitudinally of said shaft, and comprising a washer forming an outer clamping member and parts having their outer ends connected to said washer and extending longitudinally of said shaft and in interlocking relation with the outer end portions of said sleeve bearing.

4. A sewing machine as specified in claim 1 which includes a sleeve bearing interposed between said shaft and said hand wheel and pulley and includes tubular inner and outer end members surrounding said shaft, said inner end member being secured to said shaft and including an outwardly extending flange at the inner end of said sleeve hearing which serves as an inner clamping member, and said outer end member comprising an outwardly extending flange at the outer end of said sleeve bearing which serves as an outer clamping member, said sleeve bearing and inner end member comprising side by side portions extending longitudinally of the shaft and interlocking to form a splined connection beteen said inner end member and sleeve bearing, and said outer end member and sleeve bearing comprising side by side portions extending longitudinally of said shaft and interlocking to form a splined connection between said outer end member and sleeve bearing, said outer end member being moved toward said inner end member by the adjustment of the actuating element to clamp said pulley and hand wheel to said shaft.

RICHARD K. HOHMANN.

REFERENCE S CITED UNITED STATES PATENTS are of record in the Number Name Date Re. 22,822 Colegrove Dec. 24, 1946 2,247,379 I-Iohmann et a1, July 1, 1941 

